forked from osmocom/wireshark
0e7c1de08a
protocols, in addition to adding structures to the list of filterable fields. Give it an extra argument that specifies a "short name" for the protocol, for use in such places as pinfo->current_proto; the dialog box for constructing filters; the preferences tab for the protocol; and so on (although we're not yet using it in all those places). Make the preference name that appears in the preferences file and the command line for the DIAMETER protocol "diameter", not "Diameter"; the convention is that the name in question be all-lower-case. Make some routines and variables that aren't exported static. Update a comment in the ICP dissector to make it clear that the dissector won't see fragments other than the first fragment of a fragmented datagram. svn path=/trunk/; revision=2810
264 lines
6 KiB
C
264 lines
6 KiB
C
/* packet-h261.c
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*
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* Routines for ITU-T Recommendation H.261 dissection
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*
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* Copyright 2000, Philips Electronics N.V.
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* Andreas Sikkema <andreas.sikkema@philips.com>
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998 Gerald Combs
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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/*
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* This dissector tries to dissect the H.261 protocol according to Annex C
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* of ITU-T Recommendation H.225.0 (02/98)
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*
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* This dissector is called by the RTP dissector
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <glib.h>
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#include "packet.h"
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_NETINET_IN_H
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# include <netinet/in.h>
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#endif
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#include <stdio.h>
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#include <string.h>
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#include "packet-h261.h"
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/* H.261 header fields */
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static int proto_h261 = -1;
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static int hf_h261_sbit = -1;
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static int hf_h261_ebit = -1;
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static int hf_h261_ibit = -1;
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static int hf_h261_vbit = -1;
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static int hf_h261_gobn = -1;
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static int hf_h261_mbap = -1;
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static int hf_h261_quant = -1;
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static int hf_h261_hmvd = -1; /* Mislabeled in a figure in section C.3.1 as HMDV */
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static int hf_h261_vmvd = -1;
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static int hf_h261_data = -1;
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/* H.261 fields defining a sub tree */
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static gint ett_h261 = -1;
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void
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dissect_h261( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
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{
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proto_item *ti = NULL;
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proto_tree *h261_tree = NULL;
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unsigned int offset = 0;
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if ( check_col( pinfo->fd, COL_PROTOCOL ) ) {
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col_set_str( pinfo->fd, COL_PROTOCOL, "H.261" );
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}
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if ( check_col( pinfo->fd, COL_INFO) ) {
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col_set_str( pinfo->fd, COL_INFO, "H.261 message");
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}
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if ( tree ) {
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/* Using fd->pkt_len here instead of END_OF_FRAME. This variable is changed in dissect_rtp()! */
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ti = proto_tree_add_item( tree, proto_h261, tvb, offset, tvb_length( tvb ), FALSE );
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h261_tree = proto_item_add_subtree( ti, ett_h261 );
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/* SBIT 1st octet, 3 bits */
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proto_tree_add_uint( h261_tree, hf_h261_sbit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 5 );
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/* EBIT 1st octet, 3 bits */
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proto_tree_add_item( h261_tree, hf_h261_ebit, tvb, offset, 1, ( tvb_get_guint8( tvb, offset ) << 3 ) >> 5 );
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/* I flag, 1 bit */
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proto_tree_add_boolean( h261_tree, hf_h261_ibit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 2 );
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/* V flag, 1 bit */
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proto_tree_add_boolean( h261_tree, hf_h261_vbit, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 1 );
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offset++;
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/* GOBN 2nd octet, 4 bits */
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proto_tree_add_uint( h261_tree, hf_h261_gobn, tvb, offset, 1, tvb_get_guint8( tvb, offset ) >> 4 );
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/* MBAP 2nd octet, 4 bits, 3rd octet 1 bit */
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proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1,
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( tvb_get_guint8( tvb, offset ) & 15 )
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+ ( tvb_get_guint8( tvb, offset + 1 ) >> 7 ) );
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offset++;
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/* QUANT 3rd octet, 5 bits (starting at bit 2!) */
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proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 124 );
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/* HMDV 3rd octet 2 bits, 4th octet 3 bits */
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proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1,
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( ( tvb_get_guint8( tvb, offset ) << 4) >> 4 )
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+ ( tvb_get_guint8( tvb, offset ) >> 5 ) );
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offset++;
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/* VMVD 4th octet, last 5 bits */
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proto_tree_add_uint( h261_tree, hf_h261_mbap, tvb, offset, 1, tvb_get_guint8( tvb, offset ) & 31 );
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offset++;
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/* The rest of the packet is the H.261 stream */
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proto_tree_add_bytes( h261_tree, hf_h261_data, tvb, offset, tvb_length_remaining( tvb, offset ), tvb_get_ptr( tvb, offset, tvb_length_remaining( tvb, offset ) ) );
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}
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}
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void
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proto_register_h261(void)
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{
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static hf_register_info hf[] =
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{
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{
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&hf_h261_sbit,
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{
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"Start bit position",
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"h261.sbit",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_ebit,
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{
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"End bit position",
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"h261.ebit",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_ibit,
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{
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"Intra frame encoded data flag",
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"h261.i",
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FT_BOOLEAN,
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BASE_NONE,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_vbit,
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{
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"Motion vector flag",
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"h261.v",
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FT_BOOLEAN,
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BASE_NONE,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_gobn,
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{
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"GOB Number",
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"h261.gobn",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_mbap,
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{
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"Macroblock address predictor",
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"h261.mbap",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_quant,
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{
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"Quantizer",
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"h261.quant",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_hmvd,
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{
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"Horizontal motion vctor data",
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"h261.hmvd",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_vmvd,
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{
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"Vertical motion vector data",
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"h261.vmvd",
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FT_UINT8,
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BASE_DEC,
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NULL,
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0x0,
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""
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}
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},
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{
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&hf_h261_data,
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{
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"H.261 stream",
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"h261.stream",
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FT_BYTES,
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BASE_NONE,
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NULL,
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0x0,
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""
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}
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},
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};
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static gint *ett[] =
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{
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&ett_h261,
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};
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proto_h261 = proto_register_protocol("ITU-T Recommendation H.261",
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"H.261", "h261");
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proto_register_field_array(proto_h261, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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